She first mentions one of the most frequent causes: seborrheic dermatitis, an inflammatory skin condition characterized by the appearance of red patches covered with scales and dandruff. This condition is due to an overproduction of sebum, which promotes the abnormal proliferation of yeasts naturally present on the skin and scalp. This results in an inflammatory reaction, redness, and accelerated cell turnover in the scalp and skin.
Other, less common factors can also cause an itchy scalp, including psoriasis. This is an autoimmune disease that manifests as red patches and scales.
Dr. Chacon also discusses contact dermatitis, an allergic reaction or irritation linked to hair products, particularly dyes or shampoos. “Read labels carefully and know how to identify ingredients,” advises Dr. Anna Chacon. She specifically mentions sulfates, parabens, alcohol, perfumes, and synthetic dyes, substances that can cause itching, especially in cases of sensitive skin or scalp conditions.
“If you notice any of the ingredients mentioned above, especially among the first ones listed on the label (which indicates a higher concentration), it would be best to choose another product. For people with sensitive skin or scalps prone to irritation, opt for hypoallergenic, sensitive skin, or all-natural products,” recommends the specialist, who advises performing a patch test before using any hair product for the first time: apply the product to the inside of your forearm and leave it on all day. If irritation or itching occurs, do not use the product.
Lice, eczema, hives: other conditions that can cause itching.
To complete the list of skin conditions that can cause an itchy scalp, an article published by Harvard Health Publishing, the website of Harvard Medical School, also mentions atopic dermatitis, a form of eczema that can also affect the scalp. The possibility of a fungal infection, lice, or hives should also not be ruled out, as these can appear in reaction to certain foods, medications, perspiration, etc. If your itching is due to this type of condition, a doctor’s prescription will be necessary for effective treatment.
